<PRE><B>Question 26014</B>
4 hours and 48 minutes = 4.8hours
Still water speed = 15
Speed with the current = 15+x
Speed against the current = 15-x
total distance == 35
Equation:
{{{35/15+x - 35/15-x=4.8}}}
35[(15+x)+(15-x)]=4.8[(15+x)(15-x)] SIMPLIFY
{{{35(30)=4.8(-x^2+225)}}}
{{{1050=-4.8x^2+1080}}}
{{{4.8x^2=1080-1050}}}
{{{4.8x^2=30}}}
{{{4.8x^2/4.8=30/4.8}}}
{{{x^2=6.25}}}
{{{x=sqrt(6.25))}}}
x=2.5


Hence, the speed of the current is 2.5km/h.
Paul.
</PRE>